Method of and apparatus for guiding filaments



March 11, 1952 E. w. HERTENSTEIN, JR 2,588,525

METHOD OF AND APPARATUS FOR GUIDING FILAMENTS Filed June 6, 1947 3 Sheets-Sheet l 676. 3 INVEN TOR 1 an: HERTENSTE/N, JR

ATTORNEY March 1952 E. w. HERTENSTEIN, JR 2,588,525

METHOD OF AND APPARATUS FOR GUIDING FILAMENTS Filed June 6. .1947 s Sheets-Sheet 2 FIG. 2

IN [/5 N TOR 5 n4 HER mvs TE/N, JR.

BY i

A TTORNEV March 1952 E. w. HERTENSTEIN, JR 2,588,525.

METHODAOF AND APPARATUS FOR GUIDING FILAMENTS Filed June 6. 1947 3 Sheets-Sheet 5 FIG. 4

INVE N TOR 15 w. HER TENSTE/M JR.

A TTORNE V Patented Mar. 11, 1952 UNITED STATES PATENT OFFICE METHODOF AND APPARATUS FOR GUIDING FILAMENTS Edgar Hertenstein, Jr., Dundalk, Md., assignor to Western Electric Company, Incorporated, New York, N. l, a corporation or New York Application June 6, 1947(Seriafllo.753,145

This invention relates to methods of and apparatus for guiding filaments, and more particuarly to methods of and apparatus for guiding metal tapes.

In the manufacture of articles such as, for example, coaxial cables, steel tapes are sometimes drawn from supply reels mounted on serving heads and are served upon such an article. In such an operation, it is essentialto keep the tensicn of the steel tapes being served upon the are ticle uniform. In the past, as steel tapes were drawn from supply reels provided with brakes, the tension varied greatlybecause the angles at which the tape left the supply reels varied 'While the dragging force of the reels remained constant.

An object of the invention is to provide new and improved methods of and apparatus for guiding filaments.

A further object of the invention is to "provide new and improved methods of and apparatus for guiding metal. tapes.

Another object of the invention is to provide new and improved methods of and apparatus for making the tension on a steel tape being served on a coaxial cable substantially uniform even while the inclination of the tape changes with respect to the longitudinal axis of a supply reel from which the tape is drawn.

An apparatus illustrative of certain features of the invention, and by means of which methods embodying certain features of the invention may be practiced, includes a supply reel and means for creating a drag on the supply reel to tension the tape being advanced therefrom. A guide sheave positioned a predetermined distance from the supply reel serves to guide the tape to a predetermined point, and a crowned roller for contacting the tape with a line contact is positioned between the supply reel and the guide'sh'ea've in an offset position with respect thereto. The crowned roller has a line contact with the tape as distinguished from a surface contact therewith so that the tape is free to slide along the crowned roller, whereby angular variations of the tape with respect to the supply reel and the crowned roller are minimized.

A complete understanding of the invention may be obtained from the fOllOWiIlg detailed description of an apparatus forming a specific em: bodiment thereof, when read in conjunction with the appended drawings, in which:

Fig. 1 is an end view of an apparatus illustrative of certain features of the invention;

Fig. 2 is a schematic, partially developed: view of the apparatus;

52 Fig. 3 is an enlarged, fragmentary section tak en along line 3-3 of Fig. l, and

Fig. 4 is an enlarged, fragmentary, partially sectional view of a portion of the apparatus.

Referring now in detail to the drawings, there is shown therein a serving head (Fig. l) for serv' ing tapes l8 and H upon a coaxial cable l2. The serving head is rotated in a counterclockwise direction, as viewed in Fig. 1, to serve the tapes l0 and H upon the cable. The tapes Hi and I! are drawn from braked supply reels i5 and it, respectively, over crowned rollers 59 and 28, respectively, and guide pulleys 2i and 22, respectively, to the cable 12. The guide pulleys 2| and 22 direct the angle of the approach of the tapes I!) and l l, respectively, to the cable l2 and maintain this angle uniform. The crowned rollers I9 and 20 are positioned between the reels l5 and I6, respectively, and the guide pulley 2i and 22, respectively, and are offset from planes including the supply reels and the guide pulleys so that the paths of the tapes H3 and H are substantially greater in length than would be the case if the tapes were advanced directly from the supply reels to the guide pulleys.

The structure and operation of the supply reel l5, the crowned roller l9 and the guide pulley 2| are identical with those of the supply reel 16, the crowned roller 26 and the guide roller 22, respectively. Hence, only the supply reel l5, the crowned roller l9 and the guide pulley 2! will be described in detail.

The point of tangency of the guide pulley 2|, that is, the point at which the tape initially contacts the guide pulley, is substantially in alignment with the midpoint of the reel 55, and. the crowned roller i9 is offset transversely with respect to the guide pulley 2i and the reel i5, is parallel to the reel, and is centered with respect to these elements. The crowned roller i9 is pro vided with a crowned portion 38 midway between its ends. Tapered portions 3| and 32 extend from the crowned portion 30 toward flared portions 33 and 3A.

The supply reel is i mounted upon an arbor 35. A feeler roller 4! (Fig. 4) mounted on a spring-biased arm a2 is pressed against the tape on the reel l5. The amount of tape on the reel l5 controls the position of the arm 42 to which a cam 43 is rigidly secured, thereby controlling the position of the cam with respect to a cam follower urged into contact with the cam. An arm 46 of a lever 41 having a fork $8 is engaged by the cam follower. The fork 48 of the lever 41 engages a compression member 5i] which con; trolsb'y"its'positionthe braking effect of plates 5| 5| of a brake 52 of the arbor 35. When there is a full supply of the tape on the reel [5, the feeler roller and its associated elements brake the reel l6 strongly. As the supply of tape on the reel diminishes, the pressure exerted on the plates |-5l is diminished so that the component of the tension on the tape transverse to the longitudinal axis of the reel is maintained uniform. Thus, the braking force applied thereby as the supply of tape ill on the reel is lessened, so that the tension on the tape H1 is not afiected by the diameter of the supply of the tape It] on the reel Hi.

In the operation of the apparatus described hereinabove, the tape (Fig. 1) is pulled constantly from the braked supply reel IS on which it was previously woundand distributed substantially uniformly therealong. The tape H1 is payed oil of the reel from points on the reel varying continuously. That is, the tape is payed off near one of the flanges of the reel and the points of paying off thereof move along the reel toward the other flange thereof and then return in accordance with the distribution of the tape on the reel. from the midpoint of the supply reel i5 it is perpendicular to the longitudinal axis of the supply reel l5 so that the braking force on the tape from the supply reel 15 acts in alignment with the path of the tape. being payed oil the reel near one of the flanges thereof, the angle between the tape and the longitudinal axis of the reel varies substantially from a right angle. Since the portion of the tape leaving the reel is not at right angles to the longitudinal axis of the reel and the retarding force of the reel on the tape is constant, there is a slight increase in tension on the tape over that which exists when the tape is payed off perpendicular to the longitudinal axis of the reel which occurs when the tape is drawn from the midpoint of the reel. The nearer to perpendicular with respect to the longitudinal axis to the reel that the tape it: is drawn therefrom, and the smaller the edgewise angle (i. e., the angle of the tape in the plane formed by the tape) at the crowned roller, the closer is the approach to the minimum variation in tension. Hence, the least angular variation of the tape from the perpendicular to the longitudinal axis of the reel 55 and the least friction between the crowned roller and the tape that can be obtained are the conditions desired inasmuch as a substantially uniform tension on the tape H3 is desired.

The crowned roller is lengthens the path between the supply reel i5 and the guide pulley H from that which it would be if the tape were passed directly from the supply reel to the guide pulley, thereby lessening the angular variation between the tape and the longitudinal axis of the reel [5 from what it would be if the tape were advanced directly from the reel l 5 to the guide pulley 2|. Hence, this lessens the variation in the tension applied to the tape Hi by the uniform braking torque of the supply reel l5 thereon.

In order for the tape ill to have the least variation in tension, it is essential that the tape move freely along the crowned roller 58 as the tape traverses the reel. The tape I!) contacts the crowned roller is only along a line rather than to make a face contact therewith, whereby friction between the tape and the crowned roller is minimized. The opposition of the crowned roller l9 to movement of the tape longitudinally with respect to the crowned roller i9 is minimized so When the tape is being payed oil However, when the tape is 4 that edgewise lateral movement of the tape is as free as possible. The flared ends 33 and 34 (Fig. 2) prevent the tape from sliding off the ends of the crowned roller l9 when the tape is withdrawn from the convolutions adjacent to the flanges of the supply reel.

The crowned roller I9 lengthens the path of the tape between the supply reel i5 and the guide pulley 2! from that which it would have as it were advanced directly from the supply reel to the guide pulley, and since the tape contacts the crowned roller only along a line rather than by a whole face of the tape as it is drawn over the crowned roller, the friction between the tape and the roller is minimized. Thus, the tape I0 is free to slide along the crowned roller to eliminate any edgewise angles in the portion of the tape between the supply reel and the guide pulley. This minimizes the tension variations on the tape 10 as it is supplied to the coaxial cable 12. Hence, the tape is applied to the coaxial cable under a substantially uniform tension.

What is claimed is:

1. An apparatus for advancing a stifi" metal tape from a supply reel upon which it is distributed in layers and for applying the tape under uniform tension around an advancing coaxial cable core, which comprises means for rotatably supporting a reel having tape so applied thereon, means for rotating the reel supporting means about the advancing core to apply the tape helically thereupon and to withdraw the tape from the reel, means for applying a retarding force to the reel which is proportional to the radius of the outermost layer of tape on the reel, means for guiding the tape towards the core at a predetermined angle, and a crowned roller parallel to and oflset from the axis of the reel over which the tape passes in its travel from the reel to the guiding means, said crowned roller being at least as long as the lateral movement of the tape passing thereover and being so designed that the tape engages it with only a line contact whereby the tape slides freely along the roller in an edgewise direction as the tape moves to and fro while being withdrawn from the reel and the length of the path of the tape varies constantly in accordance with the position of the point at which the tape leaves the reel so as to maintain substantially uniform tension thereon.

2. Apparatus for advancing a steel tape from a supply reel upon which it is distributed in layers and for applying the tape helically under uniform tension around an advancing coaxial cable core, which comprises means for rotatably Supporting a reel having tape so applied thereon, means for rotating the reel-supporting means so as to apply the tape helically upon the core and to withdraw the tape from the reel, a follower biased to engage the outermost layer of tape on the reel, a brake controlled by the position of the follower for applying a retarding force to the reel which is proportional to the amount of tape thereon, a guide pulley aligned with the midpoint of the longitudinal axis of the reel for guiding the tape towards the core at a predetermined angle, and a roller over which the tape passes in its travel from the reel to the guide pulley, said roller being mounted parallel to and aligned with the reel but ofiset from the straight line distance from the reel to the guide pulley to lengthen the path of the tape, and said roller L being substantially as long as the reel and having a crowned portion midway between its ends and central portion towards the ends thereof at such an angle that the tape passing thereover engages the roller with only a line contact whereby the tape slides freely along the roller and the tapered portions shorten the path of the tape as the tape advances from the center towards the ends of the reel sufiiciently to maintain substantially uniform tension on the tape.

3. The method of advancing a stifi? metal tape from a supply reel upon which it is distributed in layers and of applying the tape under uniform tension around an advancing coaxial cable core, which comprises rotating the reel about the advancing core to apply the tape helically about the core and to withdraw the tape from the reel, simultaneously applying a retarding force to the reel which is progressively lessened as the layers of tape diminish so as to maintain a predetermined average tension on the tape, guiding the tape to the point where it is applied to the core, causing the tape to follow a path longer than the straight-line distance between the reel and the point of application of the tape to minimize the angular displacement of the tape from a line normal to the axis of the reel, interp-osing an elongated crowned roller in the lengthened path of the tape, and causing the tape to engage the roller with only a line contact to permit free movement of the tape along the roller whereby the length of said path varies in accordance with changes in the position of the tape as it is withdrawn from the reel and the tension on the tape is maintained substantially uniform.

4. The method of advancing a stiff metal tape from a supply reel upon which it is distributed in layers and of applying the tape under uniform tension around an advancing coaxial cable core, which comprises rotating the reel about the advancing core to apply the tape helically about the core and to withdraw the tape from the reel,.

simultaneously applying a retarding force to the reel which is progressively lessened as the layers of tape diminish so as to maintain a predetermined average tension on the tape, guiding the tape from the reel to the point where it is applied to the core along a circuitous path including an elongated crowned roller parallel to and ofiset from the reel to lengthen the path of the tape and thereby minimize angular displacement of the tape from a path normal to the axis of the reel, and causing the tape to engage the crowned roller with only a line contact whereby the tape moves freely over the surface of the roller in an edgewise direction to vary the length of said path in accordance with changes in the position of the tape as it is withdrawn from the reel and thereby to maintain the tension on the tape substantially uniform.

5. The method of advancing a steel tape from a supply reel upon which it is distributed in layers and of applying the tape under uniform tension around an advancing coaxial cable core, which comprises securing the free end of such a tape to such a core, simultaneously advancing the core along its longitudinal axis and rotating the reel about the advancing core to apply the tape helically. about the core and to withdraw the tape from the reel, maintaining a predetermined average tension on the tape as it is withdrawn from the reel, guiding the tape to its point of application to the core, causing the tape to follow a path substantially longer than the straight line disance between the reel and the point of application of the tape, interposing an elongated, centrally crowned roller at about the midpoint of said path, and causing the tape to engage the crowned roller with only a line contact to permit free movement of the tape along the roller whereby the tension on the tape causes the tape to move along the roller as the tape moves to and fro while being withdrawn from the reel and thereby varies the length of the path of the tape constantly so as to maintain substantially uniform tension thereon.

EDGAR W. HERTENSTEIN, JR.

REFERENCES CITED 2 The following references are of record in the file of this patent;

UNITED STATES PATENTS Number Name Date 227,743 Donnelly May 18, 1880 544,530 Hallanger Aug. 13, 1895 782,103 Bruner Feb. 7, 1905 2,214,340 Merwin et a1 Sept. 10, 1940 2,221,555 Reynolds Nov. 12, 1940 

